Battery and electric equipment

Abstract

The utility model discloses a battery and electric equipment, the battery comprises a battery cell and a safety assembly, the safety assembly comprises a resistor and a first temperature switch, the resistor comprises a first connecting part, a main body part and a second connecting part which are connected in sequence, and the first connecting part is electrically connected with a first electrode; the first temperature switch comprises a first conductive connecting piece, a first temperature control piece and a second conductive connecting piece, the first conductive connecting piece is electrically connected with the second connecting part, and the second conductive connecting piece is electrically connected with the second electrode; when the temperature of the first temperature control part is higher than a first preset temperature T1, the first temperature control part is in a first state, the first temperature switch is closed, and the battery is discharged; and when the temperature of the first temperature control piece is not greater than the first preset temperature T1, the first temperature control piece is in a second state, the first temperature switch is switched off, and the battery stops discharging. The battery can be discharged in a high-temperature environment through the first temperature switch and the resistor, and thermal runaway of the battery is avoided.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of new energy, in particular to a battery and an electric device provided with the battery. BACKGROUND

[0002] In the field of batteries, especially lithium ion batteries, due to high energy density and good charge-discharge cycle capability, they have been widely used in mobile phones, notebook computers, electric vehicles and other fields. Lithium ion batteries have been widely used in people's daily life due to their high energy density and long cycle life, but various battery safety problems occur frequently, so battery safety problems are gradually valued, and more and more researches on improving battery safety are carried out.

[0003] The safety problem caused by battery thermal runaway is mainly because when the battery is under high load such as high power and large current, or the battery is used in a relatively harsh environment such as high temperature, a large amount of heat will often be generated inside the battery, and the battery temperature will further rise. When the battery temperature cannot be inhibited or eliminated, the chemical system inside the battery will further deteriorate, and the internal material will be damaged, thereby causing thermal runaway, and further causing accidents such as fire and explosion of the battery. CONTENT OF THE UTILITY MODEL

[0004] Therefore, the purpose of the present application is to provide a battery provided with a safety assembly and an electric device provided with the battery, which can discharge the battery in a high-temperature environment through a first temperature switch and a resistance piece to avoid thermal runaway of the battery.

[0005] To achieve the above purpose, the present application provides the following technical solutions:

[0006] A battery comprises a battery cell and a safety assembly, the battery cell comprises a battery cell body and first and second electrodes extending from the battery cell body, and the first and second electrodes have opposite polarities;

[0007] The safety assembly comprises a resistance piece and a first temperature switch, wherein:

[0008] The resistance piece comprises a first connecting portion, a main body portion and a second connecting portion connected in sequence, and the first connecting portion is electrically connected with the first electrode;

[0009] The first temperature switch comprises a first conductive connecting piece, a first temperature control member and a second conductive connecting piece, the first conductive connecting piece is electrically connected with the second connecting portion, and the second conductive connecting piece is electrically connected with the second electrode;

[0010] When the temperature of the first temperature control member is greater than a first preset temperature T1, the first temperature control member is in a first state, and the first conductive connecting piece and the second conductive connecting piece are electrically connected through the first temperature control member.

[0011] When the temperature of the first temperature control element is not greater than the first preset temperature T1, the first temperature control element is in a second state, the first temperature control element is disconnected from the first conductive connecting element, and / or the first temperature control element is disconnected from the second conductive connecting element.

[0012] Optionally, in the battery described above, the safety assembly further comprises a second temperature switch:

[0013] The second temperature switch is connected in series with the first temperature switch, and a second temperature control element is further arranged in the second temperature switch.

[0014] When the temperature of the second temperature control element is greater than a second preset temperature T4, the second temperature control element is in a third state, and the second temperature switch is controlled to be disconnected;

[0015] When the temperature of the second temperature control element is not greater than the second preset temperature T4, the second temperature control element is in a fourth state, and the second temperature switch is controlled to be connected;

[0016] T1 < T4.

[0017] Optionally, in the battery described above, the first temperature control element comprises any one or a combination of multiple of a bimetallic strip, a trimetallic strip, and a shape memory alloy; and / or the second temperature control element comprises any one or a combination of multiple of a bimetallic strip, a trimetallic strip, and a shape memory alloy.

[0018] Optionally, in the battery described above, at least one of the first connecting portion and the second connecting portion is an integrally formed structure made of the same material as the main body portion; and / or,

[0019] At least one of the first connecting portion and the second connecting portion is an external lead connected to the main body portion by welding, bonding, or fasteners; and / or,

[0020] The first connecting portion, the main body portion, and the second connecting portion are arranged in a stacked manner to form a multi-layer structure of the resistance element; and / or,

[0021] The first temperature control element is integrally formed with the first conductive connecting element; or,

[0022] The first temperature control element is integrally formed with the second conductive connecting element.

[0023] Optionally, in the battery described above, the main body portion is a polygonal panel structure, i.e., a plate-shaped structure; and / or the surface of the main body portion is provided with a hole or groove-shaped hollow structure.

[0024] Optionally, in the battery described above, an insulating element is arranged in the hollow structure.

[0025] Optionally, in the above battery, the main body part comprises a first groove and a second groove arranged at intervals, and the main body part comprises a first side edge and a second side edge arranged oppositely;

[0026] The first groove extends from the first side edge towards the second side edge, and the inner wall surface of the first groove is spaced apart from the second side edge by a distance greater than zero;

[0027] The second groove extends from the second side edge towards the first side edge, and the inner wall surface of the second groove is spaced apart from the first side edge by a distance greater than zero.

[0028] Optionally, in the above battery, the first temperature switch further comprises a housing, and a receiving cavity is arranged inside the housing;

[0029] The first conductive connecting piece is a sheet-shaped plate body, both ends of which are a first contact end and a first connecting end, respectively, the first contact end is located in the receiving cavity, and the first connecting end extends to the outside of the housing and is electrically connected with the second connecting part;

[0030] The second conductive connecting piece is a sheet-shaped plate body, both ends of which are a second contact end and a second connecting end, respectively, the second contact end is located in the receiving cavity, and the second connecting end extends to the outside of the housing and is electrically connected with the second electrode, the second contact end has a tendency to approach and abut the first release end;

[0031] The first temperature control member is any one or a combination of multiple of a bimetallic strip, a trimetallic strip, and a shape memory alloy.

[0032] Optionally, in the above battery, the bimetallic strip is located between the first conductive connecting piece and the second conductive connecting piece, when in a first state, the bimetallic strip bends towards the side of the second conductive connecting piece, and when in a second state, the bimetallic strip bends towards the side of the first conductive connecting piece; or,

[0033] The bimetallic strip is located on the side of the second conductive connecting piece away from the first conductive connecting piece.

[0034] Optionally, in the above battery, the thickness of the main body part is any value in the range of 1 μm to 2 mm; and / or,

[0035] The thickness of the first temperature control member is any value in the range of 0.02 mm to 2 mm; and / or,

[0036] The temperature curvature of the first temperature control member is any value in the range of 1*10 -6 ~ 100*10 -6 / ℃.

[0037] Optionally, in the battery, the battery further comprises a shell, the battery cell body is located in the shell, and;

[0038] The main body part is located on the outer surface of the battery cell body and fixedly connected thereto, or is located on the inner wall of the shell and fixedly connected thereto, or is located on the outer wall of the shell and fixedly connected thereto.

[0039] And / or,

[0040] The first temperature switch is located on the top of the battery cell body and fixedly connected thereto, or is located in the interior of the battery cell body, or is located on the top of the shell and fixedly connected thereto.

[0041] Optionally, in the battery, the outer surface of the battery cell body comprises a bottom surface, and a first side surface, a second side surface, a third side surface and a fourth side surface arranged in sequence along the circumference of the bottom surface and connected end to end.

[0042] The main body part is located on the first side surface or the third side surface, or covers the first side surface, the bottom surface and the third side surface.

[0043] Optionally, in the battery, the main body part comprises at least one of a sheet resistance element, a resistance coating, a metal layer electroplated, and a metal layer chemically deposited.

[0044] Optionally, in the battery, an insulating layer is arranged between the main body part and the outer surface of the battery cell body; wherein:

[0045] The insulating layer comprises at least one of a polymer and an inorganic ceramic; and / or,

[0046] The material of the insulating layer has a thermal conductivity coefficient in the range of 0.01-0.9 W / (m·K); and / or,

[0047] The insulating layer comprises an adhesive; and / or,

[0048] The insulating layer comprises a heat-absorbing material.

[0049] Optionally, in the battery, the Ohmic impedance R2 of the resistance element is any value in the range of 0.2Ω-5Ω.

[0050] A power-consuming device comprises a body and the battery described above.

[0051] From the above technical solution can be seen, the battery and the power consumption equipment provided by the application, through the first temperature switch and the resistor component constitute a safety assembly, and in the first temperature switch, the first temperature control can present different structure state at different temperature, so as to timely response to the change of ambient temperature, and automatically control the first temperature switch to open under high temperature environment, so that the battery can be controlled to discharge, and the resistor component is used for heat dissipation, thereby avoiding the thermal runaway of the battery under high temperature environment, and the battery has higher safety. Moreover, when the ambient temperature decreases to the safety range, the first temperature control automatically restores to the original state, so that the first temperature switch is automatically disconnected, and the discharge between the positive and negative electrodes of the battery is stopped. BRIEF DESCRIPTION OF DRAWINGS

[0052] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed to be used in the embodiments or prior art description will be briefly introduced as follows. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0053] Figures 1 to 4 The structural schematic diagram of the resistor component with different shapes provided by the first specific embodiment of the present application.

[0054] Figure 5 And Figure 6 The internal structure schematic diagrams of the first temperature control switch in the closed state and the open state provided by the first specific embodiment of the present application are shown in Figs. 1 and 2 respectively.

[0055] Figure 7 And Figure 8 The internal structure schematic diagrams of the first temperature control switch in the closed state and the open state provided by the second specific embodiment of the present application are shown in Figs. 3 and 4 respectively.

[0056] Figure 9 And Figure 10 The internal structure schematic diagrams of the first temperature control switch in the closed state and the open state provided by the third specific embodiment of the present application are shown in Figs. 5 and 6 respectively.

[0057] Figure 11 The arrangement relationship schematic diagram of the cell main body, the insulating layer and the resistor component provided by the first specific embodiment of the present application is shown in Fig. 7.

[0058] Figure 12 The front view of a battery provided by the first specific embodiment of the present application is shown in Fig. 8.

[0059] Figure 13 The side view of a battery provided by the first specific embodiment of the present application is shown in Fig. 9.

[0060] Figure 14A top view of a battery according to a first specific embodiment of the present application.

[0061] Figure 15 A front view of a battery according to a fourth specific embodiment of the present application.

[0062] Figure 16 A side view of a battery according to a fourth specific embodiment of the present application.

[0063] Figure 17 A top view of a battery according to a fourth specific embodiment of the present application.

[0064] Figures 18 to 21 Structural schematic diagrams of different-shaped resistance members according to other specific embodiments of the present application. DETAILED DESCRIPTION

[0065] The present application discloses a battery provided with a safety assembly, and an electric device provided with the battery, which can discharge the battery in a high-temperature environment through a first temperature switch and a resistance member, so as to avoid thermal runaway of the battery.

[0066] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by a person of ordinary skill in the art without creative labor fall within the protection scope of the present application.

[0067] First specific embodiment

[0068] The battery provided by the first specific embodiment of the present application comprises a battery cell and a safety assembly. Please refer to Figure 1 The safety assembly comprises at least one resistance member 1 and at least one first temperature switch 2, the resistance member 1 and the first temperature switch 2 are connected in series and located between a first electrode 31 and a second electrode 32 of a battery cell body 3, and constitute a discharge circuit. Wherein:

[0069] The battery cell comprises the battery cell body 3, and the first electrode 31 and the second electrode 32 extending from the battery cell body 3, the polarities of the first electrode 31 and the second electrode 32 are opposite (if the first electrode 31 is a positive electrode, the second electrode 32 is a negative electrode; if the first electrode 31 is a negative electrode, the second electrode 32 is a positive electrode);

[0070] The resistance member 1 comprises a first connecting portion 11, a main body portion 13 and a second connecting portion 12 connected in sequence, the first connecting portion 11 is electrically connected with the first electrode 31 of the battery cell;

[0071] The first temperature switch 2 comprises a shell 26, a first pin 21 and a second pin 27 extending out of the shell 26, and a first temperature control 23 located in the shell 26. The part of the first pin 21 extending out of the shell 26 is used to be electrically connected with the second connecting part 12 of the resistance element 1, and the part of the first pin 21 located in the shell 26 is provided with a first conductive connecting element 22 (which can be an electric contact piece in particular). The part of the second pin 27 extending out of the shell 26 is used to be electrically connected with the second electrode 32 of the battery cell, and the part of the second pin 27 located in the shell 26 is provided with a second conductive connecting element 24 (which can be an electric contact cantilever in particular). The first temperature control 23 is used to control whether the first conductive connecting element 22 and the second conductive connecting element 24 are in communication. (Or in other embodiments, the second pin 27 extending out of the shell 26 can be electrically connected with the second connecting part 12 of the resistance element 1, and the first pin 21 extending out of the shell 26 can be electrically connected with the second electrode 32 of the battery cell.)

[0072] During the use of the battery:

[0073] Please refer to Figure 6 When the temperature of the first temperature control 23 is not greater than the first preset temperature T1, the first temperature control 23 is in the second state. At this time, the first temperature control 23 supports the second conductive connecting element 24 to make the second conductive connecting element 24 away from the first conductive connecting element 22, realizing the disconnection between the first pin 21 and the second pin 27, so that the first temperature switch 2 is disconnected, and the circuit in which the first temperature switch 2 and the resistance element 1 are located is disconnected.

[0074] Please refer to Figure 5 When the temperature of the first temperature control 23 is greater than the first preset temperature T1, the first temperature control 23 is in the first state. At this time, the first temperature control 23 has no supporting force (or small supporting force) on the second conductive connecting element 24, so that the second conductive connecting element 24 can be electrically connected with the first conductive connecting element 22 under the action of its own pre-stress, so that the first temperature switch 2 is closed, the first electrode 31 and the second electrode 32 of the battery cell are conducted through the first temperature switch 2 and the resistance element 1, and the battery is discharged through the resistance element 1.

[0075] It can be seen that the first temperature switch 2 is a normally open temperature switch, and the trigger temperature thereof is the first preset temperature T1. When the temperature of the environment in which the first temperature switch 2 is located is lower than the trigger temperature, the first temperature switch 2 remains in the disconnected state, and when the temperature is higher than the trigger temperature, the first temperature switch 2 is closed. In some embodiments, the value range of the first preset temperature T1 satisfies T2≤T1≤T3, T2 is the highest temperature at which the battery can normally work, and T3 is the lowest temperature at which the battery occurs thermal runaway.

[0076] The first temperature switch 2 can timely sense the change of ambient temperature and automatically control the first temperature switch 2 to open at high temperature environment, so that the battery is discharged and heat is dissipated to the outside through the resistance element 1, thereby avoiding the thermal runaway of the battery at high temperature environment and improving the safety of the battery. When the ambient temperature decreases to the safety range, the first temperature control 23 automatically returns to the original state, and the first temperature switch 2 is automatically disconnected, and the discharge between the positive and negative electrodes of the battery is stopped.

[0077] Further, the safety assembly can further include a second temperature switch, which is a normally closed temperature switch. When the temperature is lower than the trigger temperature, the second temperature switch remains in the closed state. When the temperature is higher than the trigger temperature, the second temperature switch is disconnected.

[0078] The trigger temperature of the second temperature switch is higher than that of the first temperature switch 2. The second temperature switch is connected in series with the first temperature switch 2. The second temperature switch further includes a second temperature control. When the temperature of the second temperature control is greater than a second preset temperature T4, the second temperature control is in a third state and controls the second temperature switch to be disconnected. When the temperature of the second temperature control is lower than the second preset temperature T4 (T4>T1), the second temperature control is in a fourth state and controls the second temperature switch to be closed. In specific implementation, T3≤T4≤T3+T5, T3 is the lowest temperature at which the battery occurs thermal runaway, and T5 can be any value in the range of 20℃ to 100℃. For example, T5 can be any value in the range of 21℃, 25℃, 30℃, 35℃, 40℃, 45℃, 50℃, 55℃, 60℃, 65℃, 70℃, 75℃, 80℃, 85℃, 90℃, 95℃.

[0079] Therefore, when the external environment temperature is too high, for example, the temperature of the second temperature switch and the second temperature control inside the second temperature switch reaches or is higher than T4, the discharge circuit is disconnected through the second temperature switch, and the discharge circuit is closed again when the temperature of the resistance element 1 decreases. When the external environment temperature is higher than T1 and lower than T4, the first temperature switch 2 and the second temperature switch are both in the closed state, and the discharge circuit is kept conducting. Therefore, intermittent discharge and heat dissipation are formed, which can avoid the thermal runaway of the battery due to the too high external environment temperature and avoid the safety hazard caused by the too high temperature of the resistance element 1.

[0080] In some embodiments, the second conductive connection 24 in the first temperature switch 2 is an electrically contact cantilever, which can be in the form of an elastically deformable conductive metal sheet. The first temperature control 23 in the first temperature switch 2 can be any one or a combination of multiple of a bimetallic sheet, a trimetallic sheet, and a shape memory alloy. Similarly, the second temperature control in the second temperature switch can be any one or a combination of multiple of a bimetallic sheet, a trimetallic sheet, and a shape memory alloy. Alternatively, in other embodiments, the second conductive connection 24 and the first temperature control 23 in the first temperature switch 2 can both be in the form of any one or a combination of multiple of a bimetallic sheet, a trimetallic sheet, and a shape memory alloy: when the temperature of the second conductive connection 24 and the first temperature control 23 are both not greater than the first preset temperature T1, the second conductive connection 24 and the first temperature control 23 are in a state that allows the second conductive connection 24 to be kept away from the first conductive connection 22, thereby realizing the disconnection between the first pin 21 and the second pin 27, i.e., the first temperature switch 2 is open; when the temperature of the second conductive connection 24 and the first temperature control 23 are both greater than the first preset temperature T1, the second conductive connection 24 and the first temperature control 23 are both deformed to allow the second conductive connection 24 to be electrically connected to the first conductive connection 22, thereby realizing the closure of the first temperature switch 2.

[0081] In a specific implementation, the thickness of the bimetallic sheet can be any value in the range of 0.02-2mm (e.g., 0.1mm or 0.5mm or 1mm), and the temperature curvature of the bimetallic sheet can be any value in the range of 1*10 -6 ~100*10 -6 / ℃.

[0082] In addition, the first conductive connection 22 in the first temperature switch 2, as well as the first pin 21 and the second pin 27, are all made of a highly conductive material, such as gold, copper, silver, aluminum, tinned copper, nickel-plated copper, stainless steel, etc.

[0083] Please refer to Figure 5The shell 26 of the first temperature switch 2 is preferably a packaging shell. The shell 26 is internally provided with a receiving cavity. The part of the first conductive connecting member 22 located in the shell 26 is an electric contact sheet in a sheet plate structure, and the part located outside the shell 26 forms the first pin 21, i.e. the two ends of the first conductive connecting member 22 are respectively a first contact end and a first connecting end, the first contact end is located in the receiving cavity, and the first connecting end extends to the outside of the shell 26 to form the first pin 21, which is used for electrically connecting with the second connecting part 12 of the resistance member 1. Correspondingly, the part of the second conductive connecting member 24 located in the shell 26 is an electric contact cantilever in a sheet plate structure, and the part located outside the shell 26 forms the second pin 27, i.e. the two ends of the second conductive connecting member 24 are respectively a second contact end and a second connecting end, the second contact end is located in the receiving cavity, and the second connecting end extends to the outside of the shell 26 to form the second pin 27, which is used for electrically connecting with the second electrode 32 of the battery cell, and the second contact end has a tendency to abut against the first contact end. The first temperature control member 23 is a bimetallic strip, which can control whether the second contact end and the first contact end are in contact.

[0084] For example, please refer to Figure 5 and Figure 6 The first temperature control member 23 and the second conductive connecting member 24 in the first temperature switch 2 are both in a cantilever structure, and the action amplitude can be any value in the range of 0.01-0.5 mm. The first temperature control member 23 is located between the first conductive connecting member 22 and the second conductive connecting member 24.

[0085] In some embodiments, the resistance member 1 in the battery provided by the present application is an integrally formed structural member made of the same material, i.e. the first connecting part 11, the second connecting part 12 and the main body part 13 of the resistance member 1 are integrally formed and connected.

[0086] Or in other embodiments, the first connecting part 11 and the second connecting part 12 of the resistance member 1 can be respectively external connecting leads welded or bonded or connected through fasteners with the main body part 13.

[0087] Alternatively, the first connecting part 11, the main body part 13 and the second connecting part 12 are arranged in a stacked manner, i.e. the resistance member 1 is a Figure 4 multi-layer structure as shown in the above-mentioned drawings. For example, the resistance member 1 is a heating resistance in a sheet structure, and the material can be a metal material or a carbon material that can play a role in electric conduction and heat dissipation. The metal material is preferably stainless steel, aluminum, aluminum alloy, nickel, nickel alloy, and the carbon material is preferably graphite, graphene, carbon nanotube.

[0088] In some embodiments, the main body part 13 of the resistance member 1 is a polygonal panel structure, i.e. the resistance member 1 is a Figure 1The diagram shows a single-piece plate structure without holes, grooves, or perforations. Alternatively, in other embodiments, the main body 13 of the resistor 1 can be a thin sheet structure with one or more slits, and the ohmic impedance of the resistor 1 can be adjusted by the shape and area of ​​the slits. In specific implementations, the slits on the main body 13 can be obtained by mechanical punching, laser cutting, chemical etching, or electrochemical etching.

[0089] It should be noted that the gap on the main body 13 refers to the hollow structure in the form of a channel or groove on the surface of the main body 13 of the resistor 1. The channel can be a through hole, a countersunk hole or other hole of any shape, and the shape of the channel or groove can be straight, arc or other arbitrary shape.

[0090] For example, the main body 13 is composed of Figure 2 The concave shape shown, or Figure 3 , Figure 18 , Figure 19 , Figure 20 The snake-like shape shown. Alternatively, in other embodiments, the channels or grooves on the surface of the main body 13 can be designed in other shapes, such as... Figure 21 The holes or grooves shown are distributed throughout the main body 13.

[0091] Among them, such as Figure 3 as well as Figures 18 to 20 As shown, the main body 13 of the resistor 1 includes a first groove 1310 and a second groove 1320 arranged at intervals. The main body 13 includes a first side 131 and a second side 132 disposed opposite to each other. The first groove 1310 extends from the first side 131 toward the second side 132, and the distance between the inner wall surface of the first groove 1310 and the second side 132 is greater than zero. The second groove 1320 extends from the second side 132 toward the first side 131, and the distance between the inner wall surface of the second groove 1320 and the first side 131 is greater than zero.

[0092] In specific implementations, the gap width of the aforementioned channels or grooves can be any value within the range of 10μm to 15mm, preferably any value within the range of 100μm to 1mm. For example, in some embodiments, the gap width in the aforementioned hollow structure can be designed as any value among 10μm, 20μm, 30μm, 40μm, 50μm, 60μm, 70μm, 80μm, 90μm, 100μm, 200μm, 300μm, 400μm, 500μm, 600μm, 700μm, 800μm, 900μm, 1mm, 2mm, 3mm, 4mm, 5mm, and 10mm.

[0093] The hollow structure can increase the ohmic impedance of the main body 13. It is known that the more the holes or grooves on the main body 13, the larger the hollow area, and the higher the impedance of the resistor 1. By reasonably setting the gap width and length of each position in the hollow structure, the heating power of the resistor 1 can be kept within an optimal range.

[0094] Further, the hollow structure is provided with an insulating member, which can be an insulating adhesive tape or insulating adhesive applied in the hollow structure formed by the holes or grooves of the resistor 1. In specific implementation, the material of the insulating member is preferably at least one of a polymer and a ceramic. The polymer is preferably PVDF (Polyvinylidene fluoride), PMMA (Polymethylmethacrylate, also known as acrylic or organic glass), polyimide, epoxy resin, or silica gel.

[0095] In some embodiments, the resistor 1 (especially the main body 13) can be any one of a sheet resistor, a resistive coating, a plated metal layer, or a chemically deposited metal layer.

[0096] In some embodiments, the thickness of the main body 13 of the resistor 1 is d, and 1 μm≤d≤2 mm, for example, d=2 μm or 4 μm or 5 μm or 10 μm or 15 μm or 20 μm or 25 μm or 30 μm or 40 μm or 45 μm or 50 μm or 100 μm or 200 μm or 300 μm or 400 μm or 500 μm or 600 μm or 700 μm or 800 μm or 900 μm or 1 mm or 1.5 mm. Preferably, d is any value in the range of 3 μm to 20 μm.

[0097] In some embodiments, the battery provided by the present application further includes a shell, and the above-mentioned battery core body 3 is located in the shell. Moreover, the main body 13 of the resistor 1 is located inside or on the outer surface of the battery core body 3 and is fixedly connected thereto; or the main body 13 of the resistor 1 is located on the inner wall of the battery shell and is fixedly connected thereto; or the main body 13 of the resistor 1 is located on the outer wall of the battery shell and is fixedly connected thereto.

[0098] In specific implementation, the main body 13 and the outer surface of the battery core body 3 can be fixed by adhesion, clamping, welding, or fastener connection, or the main body 13 and the inner wall of the battery shell can be fixed by adhesion, clamping, welding, or fastener connection.

[0099] In addition, in some embodiments, the first temperature switch 2 may be disposed on the top of the cell body 3 (e.g., outside the top seal edge) and fixedly connected thereto; or, the first temperature switch 2 may be located inside the cell body 3; or, the first temperature switch 2 may be located on the top of the battery casing and fixedly connected thereto.

[0100] For example, in some embodiments, the outer surface of the battery cell body 3 includes a bottom surface and a first side surface, a second side surface, a third side surface, and a fourth side surface arranged sequentially along the circumference of the bottom surface and connected end to end; the first side surface and the third side surface are opposite each other and have relatively large areas, while the first side surface and the second side surface are opposite each other and have relatively small areas. In this case, the main body 13 can be fitted and disposed on any side surface of the battery cell body 3, such as the first side surface (see [reference]). Figures 12 to 14 Alternatively, the main body 13 can be attached to the first and bottom surfaces and the third surface of the cell body 3 (see also...). Figures 15 to 16 Alternatively, the main body 13 may be attached to the second side, bottom, and fourth side of the battery cell body 3.

[0101] Please see Figures 12 to 14 In some embodiments, the main body 13 is attached to the first side of the cell body 3, the first connecting part 11 is located on the top of the cell body 3 and is connected in series with the first temperature switch 2 and the first electrode 31, and the second connecting part 12 is located on the top of the cell body 3 and is connected to the second electrode 32. In this case, both the first connecting part 11 and the second connecting part 12 are located on the top of the first side of the cell body 3 and extend toward the first electrode 31 and the second electrode 32, respectively. The first temperature switch 2 is disposed in any area of ​​the top of the cell body 3 or on the top sealing edge 30 (see [reference]). Figure 12 The two ends of the first temperature switch 2 are welded to the first connecting part 11 and the first electrode 31, respectively. The end of the second connecting part 12 away from the main body 13 is welded to the second electrode 32. The specific locations of the above welding points can be found in [reference needed]. Figures 12 to 14 The welding zone h in the middle.

[0102] Please see Figures 15 to 17 In some embodiments, the main body 13 is attached to the first side, bottom, and third side of the cell body 3. The first connecting part 11 is located on the top of the cell body 3 and is connected in series with the first temperature switch 2 and the first electrode 31. The second connecting part 12 is located on the top of the cell body 3 and is connected to the second electrode 32. In this case, the first connecting part 11 is located on the top of the first side of the cell body 3 and extends towards the first electrode 31, and the second connecting part 12 is located on the top of the third side of the cell body 3 and extends towards the second electrode 32. The first temperature switch 2 is located in any area of ​​the top of the cell body 3 or on the top sealing edge 30 (see [reference]). Figure 15), the first temperature switch 2 is welded at two ends thereof to the first connecting portion 11 and the first electrode 31, and the second connecting portion 12 is welded at one end thereof away from the third side surface of the battery core body 3 and the second electrode 32. The specific positions of the above-mentioned welding areas can be seen from the welding areas h in Figures 15 to 17

[0103] Please refer to Figure 11 In some embodiments, an insulating layer 4 is arranged between the main body 13 and the outer surface of the battery core body 3. The insulating layer 4 comprises at least one of a polymer and an inorganic ceramic, and the material of the insulating layer 4 has a thermal conductivity coefficient of 0.01-0.9 W / (m·K), which can prevent the heat generated by the resistance element 1 from heating the battery core body, thereby further improving the safety performance.

[0104] Further, in some embodiments, the insulating layer 4 can also have a bonding effect, and its material comprises an adhesive, which can bond the battery core body 3 and the resistance element 1 in the sheet structure together, and the bonding force is ≥0.1 N / m, for example, the adhesive of the insulating layer 4 is a polymer material.

[0105] Alternatively, in some embodiments, the insulating layer 4 can also comprise a heat-absorbing material, such as a phase change heat-absorbing material or a chemical heat-absorbing material, thereby further improving the safety performance of the battery. It should be noted that the heat-absorbing material refers to a material that can effectively absorb and release heat, or in other words, a material that can absorb heat when the temperature rises and release heat when the temperature drops. They usually have high specific heat capacity or latent heat characteristics, can effectively store and release heat within a certain temperature range, and can maintain stable performance in multiple heat absorption and release cycles without aging or failure.

[0106] Specifically, when the temperature of the battery core body 3 is high, the insulating layer 4 can absorb heat and conduct the heat to the main body 13 and the surrounding air, thereby playing a certain heat dissipation effect on the battery core body 3; when the temperature of the main body 13 is high, the insulating layer 4 can absorb the heat of the main body 13, avoiding the direct transmission of the heat of the main body 13 to the battery core body 3, thereby playing a certain heat insulation effect between the main body 13 and the battery core body 3 through the insulating layer 4, avoiding the heating of the main body 13 to the battery core body 3. In specific implementation, the insulating layer 4 can be any heat-absorbing material such as paraffin, fatty acid, polyethylene glycol, polyethylene, polyethylene wax, polypropylene, or the insulating layer 4 can also be any heat-absorbing and heat-conducting adhesive such as epoxy resin-based, silicone-based, polyurethane-based, and acrylic-based.

[0107] ​In some embodiments, the relationship between the DC internal resistance R0 of the battery cell body 3 under full charge and at 25°C, the ohmic impedance R1 of the first temperature switch 2, and the ohmic impedance R2 of the sheet-structure resistor 1 satisfies: 2(R0+R1)≤R2≤1000(R0+R1), where R1 is any value within the range of 1 to 100Ω, and the units of R0, R1, and R2 are all mΩ. In some embodiments, the battery capacity is set to Q (unit: mAh), the DC internal resistance DCIR of the battery under full charge and at 25°C is set to R0 (unit: mΩ), the ohmic impedance of the first temperature switch 2 is set to R1 (unit: mΩ), and the ohmic impedance of the sheet-structure resistor 1 is set to R2 (unit: mΩ). Then, the optimal relationship between R2 and Q satisfies: Q(R0+R1) / 5000≤R2≤5000(R0+R1). For example, in some embodiments, R2 is any value within the range of 0.2Ω to 5Ω. If R2 is too small, it will easily lead to a large amount of heat generation in a short period of time, causing the battery to heat up quickly and fail; if R2 is too large, it will not discharge sufficiently in a short period of time, failing to reduce the battery energy, and the battery will still easily fail at high temperatures.

[0108] It should be noted that the batteries provided in the embodiments of this application may be, but are not limited to, lithium-ion batteries, lithium metal batteries, lead-acid batteries, nickel-metal hydride batteries, lithium-sulfur batteries, lithium-air batteries, sodium-ion batteries, solid-state batteries, etc.

[0109] Second specific embodiment

[0110] like Figure 7 and Figure 8 As shown, in the second specific embodiment, the first temperature control element 23 in the first temperature switch 2 is an arc-shaped structure with both ends being free, located between the second conductive connector 24 and the first conductive connector 22. Furthermore, the contact area 231 of the first temperature control element 23 is located at the apex of the arc-shaped area in its middle region, and the shape of the first temperature control element 23 changes with temperature. For example:

[0111] When the ambient temperature is high enough to reach the trigger temperature of the first temperature switch 2, the first temperature control 23 is in the first state (see [reference]). Figure 7 The first temperature control 23 bends toward the side where the second conductive connector 24 is located, and the two ends of the first temperature control 23 are away from the second conductive connector 24 and are located in the groove on the inner wall of the housing 26, thereby controlling the second conductive connector 24 to contact the first conductive connector 22, and the first temperature switch 2 closes.

[0112] When the ambient temperature is lower than the trigger temperature of the first temperature switch 2, the first temperature control 23 is in the second state (see [reference]). Figure 8), the first temperature control 23 is bent towards the side where the first conductive connecting piece 22 is located, the two ends of the first temperature control 23 are raised and support the second conductive connecting piece 24, thereby controlling the second conductive connecting piece 24 to move away from the first conductive connecting piece 22, and the first temperature switch 2 is disconnected.

[0113] Third embodiment

[0114] As shown in Figure 9 and Figure 10 , in the third embodiment, the first temperature control 23 in the first temperature switch 2 is in an arc-shaped structure, and is located on the side where the second conductive connecting piece 24 faces away from the first conductive connecting piece 22. Moreover, the abutting area 231 of the first temperature control 23 is located at the end, and the bending degree of the first temperature control 23 changes with the temperature. For example:

[0115] When the ambient temperature is high and reaches the trigger temperature of the first temperature switch 2, the first temperature control 23 is in the first state (see Figure 9 ), the bending degree of the first temperature control 23 is large, thereby extruding the second conductive connecting piece 24 to contact the first conductive connecting piece 22, at this time, the first temperature switch 2 is in a closed state;

[0116] When the ambient temperature is lower than the trigger temperature of the first temperature switch 2, the first temperature control 23 is in the second state (see Figure 10 ), the bending degree of the first temperature control 23 is small, and the abutting area 231 thereof moves slightly in the direction away from the second conductive connecting piece 24, thereby the second conductive connecting piece 24 moves away from the first conductive connecting piece 22 under the action of the elastic restoring force thereof, at this time, the first temperature switch 2 is in a disconnected state.

[0117] In summary, the embodiments of the present application also provide a power-using equipment, which comprises a body and the battery as described in any of the above embodiments.

[0118] In specific implementation, lithium cobaltate can be selected as the positive electrode material of the lithium battery, graphite negative electrode material can be selected as the negative electrode material of the lithium battery, the cell structure adopts a winding structure, the outer packaging adopts a conventional aluminum plastic film outer packaging, and a lithium ion battery sample is prepared for testing. In the following, some specific embodiments and comparative examples in the testing process are taken as examples for comparative analysis.

[0119]

[0120]

[0121]

[0122] Embodiments 1 to 13

[0123] A battery is respectively provided in each of embodiments 1 to 13, and the safety assembly described above is arranged between the positive and negative electrodes of the battery, i.e. the first temperature switch 2 and the resistance element 1 described above are arranged between the positive and negative tabs of the cell body 3 of each battery. Among them, the cell body 3 in embodiments 1 to 13 is completely the same, the first temperature switch 2 is completely the same, and a 10 μm thick metal stainless steel foil is used as the resistance element 1 with a sheet structure. Among them, the first connecting part 11 of the resistance element 1 is connected with the positive tab of the cell, the second connecting part 12 is connected with the first temperature switch 2, and the first temperature switch 2 is connected with the negative tab of the cell. The first temperature switch 2 is the normally open type temperature switch provided with the first temperature control 23 described above, and the trigger temperature is 85℃; in the resistance element 1, a gap with a width of 0.5 mm is engraved on the stainless steel foil by laser, so that the ohmic impedance between the two lead-out ends of the metal aluminum foil (i.e. the first connecting part 11 and the second connecting part 12 in the resistance element 1) is a preset value.

[0124] The difference between embodiments 1 to 13 is only that the ohmic impedance value of the resistance element 1 is different, and the ohmic impedance value of the resistance element 1 in embodiments 1 to 13 is 5.2Ω, 5.0Ω, 2.0Ω, 1.8Ω, 1.6Ω, 1.4Ω, 1.2Ω, 1.0Ω, 0.8Ω, 0.6Ω, 0.4Ω, 0.2Ω, 0.1Ω respectively.

[0125] From the test results in the above table, it can be seen that the ohmic impedance value of the resistance element 1 is too large or too small, which will reduce the pass rate of the battery in the hot box safety test process, and the best range is 0.2Ω

[0126]

[0127] Embodiments 14 to 16

[0128] Compared with the above embodiment 10, the difference between embodiments 14 to 16 is only that the trigger temperature of the first temperature switch 2 is different. Among them, the trigger temperature of the first temperature switch 2 in embodiments 14 to 16 is 75℃, 95℃, 105℃ respectively.

[0129] From the test results in the above table, it can be seen that the lower the trigger temperature of the first temperature switch 2, the higher the pass rate of the battery in the hot box safety test process. In order to make the battery adapt to a higher temperature environment as much as possible, the trigger temperature of the first temperature switch 2 is best set in the range of 75℃ to 85℃ during specific implementation, and in some cases, for example, when the environmental temperature is not higher than 130℃, the trigger temperature of the first temperature switch 2 can also be set to any value within the range of 85℃ to 105℃.

[0130] Comparative example 1

[0131] ​The difference of Comparative Example 1 compared to Examples 1 to 16 above is that the battery does not contain the safety assembly described above, i.e. no first temperature switch 2 and resistor 1 are arranged between the positive and negative electrode tabs of the cell.

[0132] From the test results in the above table, it can be seen that arranging the safety assembly consisting of a temperature switch and a resistor 1 between the positive and negative electrode tabs of the cell can effectively improve the pass rate of the thermal chamber safety test of the battery.

[0133] Finally, it should be noted that the terms such as first and second, etc. are used herein only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Also, the terms "comprising", "containing" or any other variant thereof are intended to cover non-exclusive inclusion, so that a process, method, article or apparatus including a list of elements does not only include those elements, but also includes other elements not explicitly listed, or further includes elements inherent in such a process, method, article or apparatus. Without more limitations, the element defined by the phrase "comprising a" does not exclude the presence of additional identical elements in the process, method, article or apparatus including the element.

[0134] The various embodiments in the specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments and the technical content associated with the differences. The same or similar parts between the various embodiments can be referred to each other.

[0135] The above description of the disclosed embodiments enables a person skilled in the art to implement or use the present application. Various modifications to the embodiments will be apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to the embodiments shown herein, but will conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A battery, characterized by, The safety assembly comprises a resistor (1) and a first temperature switch (2), wherein: The resistor (1) comprises a first connecting part (11), a main body part (13) and a second connecting part (12) connected in sequence, and the first connecting part (11) is electrically connected with the first electrode (31); The first temperature switch (2) comprises a first conductive connecting part (22), a first temperature control part (23) and a second conductive connecting part (24), the first conductive connecting part (22) is electrically connected with the second connecting part (12), and the second conductive connecting part (24) is electrically connected with the second electrode (32); When the temperature of the first temperature control part (23) is greater than a first preset temperature T1, the first temperature control part (23) is in a first state, and the first conductive connecting part (22) and the second conductive connecting part (24) are electrically connected through the first temperature control part (23); When the temperature of the first temperature control part (23) is not greater than the first preset temperature T1, the first temperature control part (23) is in a second state, and the first temperature control part (23) is disconnected with the first conductive connecting part (22) and / or the second conductive connecting part (24). The safety assembly further comprises a second temperature switch:

2. The battery of claim 1, wherein, The second temperature switch is connected in series with the first temperature switch (2), and a second temperature control part is further arranged in the second temperature switch: When the temperature of the second temperature control part is greater than a second preset temperature T4, the second temperature control part is in a third state, and the second temperature switch is controlled to be disconnected; When the temperature of the second temperature control part is not greater than the second preset temperature T4, the second temperature control part is in a fourth state, and the second temperature switch is controlled to be connected; T1 < T4. At least one of the first connecting part (11) and the second connecting part (12) is an integrally formed structure part made of the same material as the main body part (13); and / or, 3. The battery of claim 1, wherein, At least one of the first connecting part (11) and the second connecting part (12) is an external lead wire welded, adhered or connected through a fastener with the main body part (13); and / or, The first connecting part (11), the main body part (13) and the second connecting part (12) are arranged in a stacked manner to form the resistor (1) with a multi-layer structure; and / or, The first temperature control part (23) is integrally formed with the first conductive connecting part (22), or the first temperature control part (23) is integrally formed with the second conductive connecting part (24). The main body part (13) is a plate-shaped structure; and / or, 4. The battery of claim 1, wherein, The main body part (13) is provided with a hole or groove-shaped hollow structure on the surface. An insulating part is arranged in the hollow structure.

5. The battery of claim 4, wherein, ​ 6. The battery of claim 4, wherein, The main body (13) comprises a first side (131) and a second side (132) arranged oppositely, and a first groove (1310) and a second groove (1320) arranged at intervals; The first groove (1310) extends from the first side (131) to the second side (132), and the inner wall surface of the first groove (1310) is spaced apart from the second side (132) by more than zero; The second groove (1320) extends from the second side (132) to the first side (131), and the inner wall surface of the second groove (1320) is spaced apart from the first side (131) by more than zero.

7. The battery of claim 2, wherein, The first temperature switch (2) further comprises a shell (26) provided with a receiving cavity inside; The first conductive connecting piece (22) is a sheet-shaped plate body, and its two ends are a first contact end and a first connecting end, respectively, the first contact end is located in the receiving cavity, and the first connecting end extends to the outside of the shell (26) and is electrically connected with the second connecting part (12); The second conductive connecting piece (24) is a sheet-shaped plate body, and its two ends are a second contact end and a second connecting end, respectively, the second contact end is located in the receiving cavity, and the second connecting end extends to the outside of the shell (26) and is electrically connected with the second electrode (32), the second contact end has a tendency to approach and abut the first contact end; The first temperature control (23) comprises any one or a combination of more than one of a bimetallic strip, a trimetallic strip, and a shape memory alloy; and / or, the second temperature control comprises any one or a combination of more than one of a bimetallic strip, a trimetallic strip, and a shape memory alloy.

8. The battery according to any one of claims 1 to 7, characterized in that, The thickness of the main body (13) is any value in the range of 1 μm to 2 mm; and / or, The thickness of the first temperature control (23) is any value in the range of 0.02 to 2 mm; and / or, The temperature curvature of the first temperature control (23) is 1 10 -6 ~100 10 -6 any value in the range of 0-10 °C; and / or, The ohmic impedance R2 of the resistance piece (1) is any value in the range of 0.2 Ω to 5 Ω.

9. The battery of claim 1, wherein, The battery further comprises a shell, the cell body (3) is located in the shell, and: The main body (13) is located on the outer surface of the cell body (3) and is fixedly connected therewith; or, the main body (13) is located on the inner wall of the shell and is fixedly connected therewith; or, the main body (13) is located on the outer wall of the shell and is fixedly connected therewith; And / or, The first temperature switch (2) is located on the top of the cell body (3) and is fixedly connected therewith; or, the first temperature switch (2) is located in the cell body (3); or, the first temperature switch (2) is located on the top of the shell and is fixedly connected therewith.

10. The battery of claim 9, wherein, The outer surface of the cell body (3) comprises a bottom surface, and a first side surface, a second side surface, a third side surface, and a fourth side surface arranged in sequence and connected end to end along the circumference of the bottom surface; The main body (13) is located on the first side surface or the third side surface; or, the main body (13) covers the first side surface, the bottom surface, and the third side surface.

11. The battery of claim 1, wherein, The main body (13) comprises at least one of a sheet resistance element, a resistive coating, a plated metal layer, and a chemically deposited metal layer.

12. The battery of claim 1, wherein, An insulating layer (4) is arranged between the main body (13) and the outer surface of the battery cell body (3).

13. The battery of claim 12, wherein, The insulating layer (4) comprises a polymer.

14. The battery of claim 12, wherein, The insulating layer (4) comprises an inorganic ceramic.

15. The battery of claim 12, wherein, The material of the insulating layer (4) has a thermal conductivity coefficient in the range of 0.01-0.9 W / (m·K).

16. The battery of claim 12, wherein, The insulating layer (4) comprises an adhesive.

17. The battery of claim 12, wherein, The insulating layer (4) comprises a heat-absorbing material.

18. An electrical device comprising a body, characterised in that The battery according to any one of claims 1-11.

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